Excessive daytime sleepiness works together with other sleep disorders in determining sleepiness-related events in shift workers

Background: Shift-workers may experience sleep disturbances more frequently than day-workers. Interactions between obstructive sleep apnea (OSA), shift-work and other factors promoting sleepiness have never been studied. The present study was designed to assess the prevalence of excessive daytime sleepiness (EDS), high risk for OSA (HR) and insomnia in shift-workers and day-workers and to evaluate their mutual effects on the risk of home-to-work commuting car accidents or episodes of falling asleep during work. Methods. Workers (153 shift-workers, 85 day-workers) were evaluated for the presence of sleep disorders including HR and EDS. The relationships between sleepiness-related events, shift-work and sleep disorders were investigated by path analysis. Results. Forty-nine subjects had HR. EDS was more frequent in shift-workers than in day-workers (16.3% vs. 5.9%, P=0.01) and in workers with HR (28.6% vs. 8.4%, P